This is a movie trailer for the 1958 Lewis Milestone Korean War epic, "Pork Chop Hill", starring Gregory Peck, who also co-produced it.
It's the kind of film made about the Korean War prior to Robert Altman's "M.A.S.H.", which was adapted into the long-running tv series of the same name, beginning in 1972, in that its politics are uncompromisingly anti-Communist, and its depictions of the Chinese and North Koreans are, at best, on the unflattering side.
This is something that the tv version of "MASH" tried, a bit too hard, really, to correct, and ended up making the South Korean soldiery among the main nasties as a result.
In fact, one of the less happy legacies of the tv version of "MASH" is that the Koreans ended up as usually either victims, comic relief or villains.
Be seeing you.